This invention relates to providing for telephone calls over packet-switched networks, such as the Internet, and in particular to call signaling for such telephone calls.
Conventionally, telephone calls, including voice calls, fax transmissions, and data transmissions between computers, are carried over circuit switched telephone networks. Circuit switched telephone networks provide a very reliable switched path between endpoints. However, the cost of telephone calls over circuit switched telephone networks over more than short distances, particularly long-distance and international calling, is very significant.
One solution that has been proposed is providing telephone connections via packet-switched networks, such as the Internet. In packet-switched networks, messages are broken into individual packets, which are separately transmitted over the network to a destination. Alternative pricing schemes are available in such networks.
In existing techniques for telephony over packet-switched networks, a telephone user must take certain steps that render using such networks less desirable than circuit switched telephone networks. For example, a user must employ a personal computer with a connection to the Internet rather than a conventional telephone. Alternatively, a user must complete a conventional local telephone call to a server, and then input the destination telephone number to complete the call. Either of these processes represent significant inconvenience for the user. Also, fax machines, which are specifically designed to complete calls directly over a public switched telephone network (PSTN) must be individually reprogrammed, or may not be programmable to take advantage of these techniques.
In a method according to the invention, a telephone call from a first telephone device to a second telephone device is carried out via a packet-switched network with call signaling identical to that obtained in a telephone call via a circuit-switched network. A telephone call is initiated from a telephone device which is connected To a first gateway. The first gateway receives dialed digits from the telephone device, and identifies an address on a packet switched network of a second gateway associated with a receiving telephone device identified by the dialed digits. The first gateway contacts the second gateway via the packet-switched network. The second gateway initiates a circuit-switched telephone connection to the receiving telephone device. When a ringing signal or busy signal is received from the receiving telephone device by the second gateway, the second gateway provides a signal via the packet-switched network to the first gateway. The first gateway provides the corresponding signal to the initiating telephone device. The method is thereby transparent to the user of the initiating telephone device.
In a method according to the invention, a telephone call from a first telephone device is facilitated over a packet-switched network. A telephone call is received at a first gateway. The first gateway receives dialed digits, identifies an address on a packet-switched network of a second gateway associated with a receiving telephone device identified by the dialed digits. The first gateway sends a signal on the packet-switched network to the second gateway. When the first gateway receives a signal over the packet-switched network indicating that the second gateway is receiving a ringing signal or busy signal from a receiving telephone device, the first gateway provides the corresponding signal to the initiating telephone device.
In a system according to the invention, a first gateway server is connected to a first telephone device and to a packet-switched network. The first gateway server is configured to detect a telephone call from the first telephone device, to identify an address on a packet-switched network of a second gateway associated with a receiving telephone device identified by the first telephone device, to send a signal on the packet-switched network to the second gateway requesting a telephone connection to the receiving telephone device, and, on receiving a signal over packet-switched network indicating that the second gateway is receiving a ringing signal or a busy signal from a receiving telephone device, providing a corresponding signal to the first telephone device.